X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;ds=sidebyside;f=src%2Fevaluate.cpp;h=6d95fd58cb6cca53a1c968d7fbdaddf142f1e934;hb=939b621e5c67e9ef89b409fd773d38058341906c;hp=e75251f472a8b532e91226b78a76ea3f8cc2fd19;hpb=fecefbb99cb0147f37d6895765a315f34c935786;p=stockfish
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index e75251f4..6d95fd58 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -17,15 +17,11 @@
along with this program. If not, see .
*/
-
-////
-//// Includes
-////
-
#include
#include
#include
#include
+#include
#include "bitcount.h"
#include "evaluate.h"
@@ -34,18 +30,14 @@
#include "thread.h"
#include "ucioption.h"
-
-////
-//// Local definitions
-////
-
namespace {
// Struct EvalInfo contains various information computed and collected
// by the evaluation functions.
struct EvalInfo {
- // Pointer to pawn hash table entry
+ // Pointers to material and pawn hash table entries
+ MaterialInfo* mi;
PawnInfo* pi;
// attackedBy[color][piece type] is a bitboard representing all squares
@@ -53,20 +45,20 @@ namespace {
// all squares attacked by the given color.
Bitboard attackedBy[2][8];
- // kingZone[color] is the zone around the enemy king which is considered
+ // kingRing[color] is the zone around the king which is considered
// by the king safety evaluation. This consists of the squares directly
// adjacent to the king, and the three (or two, for a king on an edge file)
// squares two ranks in front of the king. For instance, if black's king
- // is on g8, kingZone[WHITE] is a bitboard containing the squares f8, h8,
+ // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
// f7, g7, h7, f6, g6 and h6.
- Bitboard kingZone[2];
+ Bitboard kingRing[2];
// kingAttackersCount[color] is the number of pieces of the given color
- // which attack a square in the kingZone of the enemy king.
+ // which attack a square in the kingRing of the enemy king.
int kingAttackersCount[2];
// kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
- // given color which attack a square in the kingZone of the enemy king. The
+ // given color which attack a square in the kingRing of the enemy king. The
// weights of the individual piece types are given by the variables
// QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
// KnightAttackWeight in evaluate.cpp
@@ -84,7 +76,7 @@ namespace {
const int GrainSize = 8;
// Evaluation weights, initialized from UCI options
- enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
+ enum { Mobility, PassedPawns, Space, KingDangerUs, KingDangerThem };
Score Weights[6];
typedef Value V;
@@ -97,7 +89,7 @@ namespace {
//
// Values modified by Joona Kiiski
const Score WeightsInternal[] = {
- S(248, 271), S(233, 201), S(252, 259), S(46, 0), S(247, 0), S(259, 0)
+ S(252, 344), S(216, 266), S(46, 0), S(247, 0), S(259, 0)
};
// MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
@@ -151,9 +143,9 @@ namespace {
{ S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0, 0) } // QUEEN
};
- // ThreatedByPawnPenalty[PieceType] contains a penalty according to which
+ // ThreatenedByPawnPenalty[PieceType] contains a penalty according to which
// piece type is attacked by an enemy pawn.
- const Score ThreatedByPawnPenalty[] = {
+ const Score ThreatenedByPawnPenalty[] = {
S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
};
@@ -224,7 +216,7 @@ namespace {
// TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
// evaluation terms, used when tracing.
- Score TracedTerms[2][16];
+ Score TracedScores[2][16];
std::stringstream TraceStream;
enum TracedType {
@@ -261,6 +253,8 @@ namespace {
Value scale_by_game_phase(const Score& v, Phase ph, ScaleFactor sf);
Score weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight);
void init_safety();
+ double to_cp(Value v);
+ void trace_add(int idx, Score term_w, Score term_b = SCORE_ZERO);
}
@@ -269,107 +263,87 @@ namespace {
/// between them based on the remaining material.
Value evaluate(const Position& pos, Value& margin) {
- return CpuHasPOPCNT ? do_evaluate(pos, margin)
- : do_evaluate(pos, margin);
+ return CpuHasPOPCNT ? do_evaluate(pos, margin)
+ : do_evaluate(pos, margin);
}
namespace {
-double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
-
-void trace_add(int idx, Score term_w, Score term_b = Score(0)) {
-
- TracedTerms[WHITE][idx] = term_w;
- TracedTerms[BLACK][idx] = term_b;
-}
-
template
Value do_evaluate(const Position& pos, Value& margin) {
EvalInfo ei;
Value margins[2];
- Score mobilityWhite, mobilityBlack;
+ Score score, mobilityWhite, mobilityBlack;
- assert(pos.is_ok());
assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
- assert(!pos.is_check());
+ assert(!pos.in_check());
- // Initialize value by reading the incrementally updated scores included
+ // Initialize score by reading the incrementally updated scores included
// in the position object (material + piece square tables).
- Score bonus = pos.value();
+ score = pos.value();
// margins[] store the uncertainty estimation of position's evaluation
// that typically is used by the search for pruning decisions.
margins[WHITE] = margins[BLACK] = VALUE_ZERO;
// Probe the material hash table
- MaterialInfo* mi = ThreadsMgr[pos.thread()].materialTable.get_material_info(pos);
- bonus += mi->material_value();
+ ei.mi = Threads[pos.thread()].materialTable.get_material_info(pos);
+ score += ei.mi->material_value();
// If we have a specialized evaluation function for the current material
// configuration, call it and return.
- if (mi->specialized_eval_exists())
+ if (ei.mi->specialized_eval_exists())
{
margin = VALUE_ZERO;
- return mi->evaluate(pos);
+ return ei.mi->evaluate(pos);
}
// Probe the pawn hash table
- ei.pi = ThreadsMgr[pos.thread()].pawnTable.get_pawn_info(pos);
- bonus += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
+ ei.pi = Threads[pos.thread()].pawnTable.get_pawn_info(pos);
+ score += ei.pi->pawns_value();
// Initialize attack and king safety bitboards
init_eval_info(pos, ei);
init_eval_info(pos, ei);
// Evaluate pieces and mobility
- bonus += evaluate_pieces_of_color(pos, ei, mobilityWhite)
+ score += evaluate_pieces_of_color(pos, ei, mobilityWhite)
- evaluate_pieces_of_color(pos, ei, mobilityBlack);
- bonus += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
+ score += apply_weight(mobilityWhite - mobilityBlack, Weights[Mobility]);
// Evaluate kings after all other pieces because we need complete attack
// information when computing the king safety evaluation.
- bonus += evaluate_king(pos, ei, margins)
+ score += evaluate_king(pos, ei, margins)
- evaluate_king(pos, ei, margins);
// Evaluate tactical threats, we need full attack information including king
- bonus += evaluate_threats(pos, ei)
+ score += evaluate_threats(pos, ei)
- evaluate_threats(pos, ei);
// Evaluate passed pawns, we need full attack information including king
- bonus += evaluate_passed_pawns(pos, ei)
+ score += evaluate_passed_pawns(pos, ei)
- evaluate_passed_pawns(pos, ei);
// If one side has only a king, check whether exists any unstoppable passed pawn
if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
- {
- bonus += evaluate_unstoppable_pawns(pos, ei);
-
- if (Trace)
- trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
- }
+ score += evaluate_unstoppable_pawns(pos, ei);
// Evaluate space for both sides, only in middle-game.
- if (mi->space_weight())
+ if (ei.mi->space_weight())
{
- int s_w = evaluate_space(pos, ei);
- int s_b = evaluate_space(pos, ei);
- bonus += apply_weight(make_score((s_w - s_b) * mi->space_weight(), 0), Weights[Space]);
-
- if (Trace)
- trace_add(SPACE, apply_weight(make_score(s_w * mi->space_weight(), make_score(0, 0)), Weights[Space]),
- apply_weight(make_score(s_b * mi->space_weight(), make_score(0, 0)), Weights[Space]));
+ int s = evaluate_space(pos, ei) - evaluate_space(pos, ei);
+ score += apply_weight(make_score(s * ei.mi->space_weight(), 0), Weights[Space]);
}
// Scale winning side if position is more drawish that what it appears
- ScaleFactor sf = eg_value(bonus) > VALUE_DRAW ? mi->scale_factor(pos, WHITE)
- : mi->scale_factor(pos, BLACK);
- Phase phase = mi->game_phase();
+ ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
+ : ei.mi->scale_factor(pos, BLACK);
// If we don't already have an unusual scale factor, check for opposite
// colored bishop endgames, and use a lower scale for those.
- if ( phase < PHASE_MIDGAME
+ if ( ei.mi->game_phase() < PHASE_MIDGAME
&& pos.opposite_colored_bishops()
&& sf == SCALE_FACTOR_NORMAL)
{
@@ -390,22 +364,27 @@ Value do_evaluate(const Position& pos, Value& margin) {
// Interpolate between the middle game and the endgame score
margin = margins[pos.side_to_move()];
- Value v = scale_by_game_phase(bonus, phase, sf);
+ Value v = scale_by_game_phase(score, ei.mi->game_phase(), sf);
+ // In case of tracing add all single evaluation contributions for both white and black
if (Trace)
{
trace_add(PST, pos.value());
- trace_add(IMBALANCE, mi->material_value());
- trace_add(PAWN, apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]));
+ trace_add(IMBALANCE, ei.mi->material_value());
+ trace_add(PAWN, ei.pi->pawns_value());
trace_add(MOBILITY, apply_weight(mobilityWhite, Weights[Mobility]), apply_weight(mobilityBlack, Weights[Mobility]));
trace_add(THREAT, evaluate_threats(pos, ei), evaluate_threats(pos, ei));
trace_add(PASSED, evaluate_passed_pawns(pos, ei), evaluate_passed_pawns(pos, ei));
- trace_add(TOTAL, bonus);
+ trace_add(UNSTOPPABLE, evaluate_unstoppable_pawns(pos, ei));
+ Score w = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0);
+ Score b = make_score(ei.mi->space_weight() * evaluate_space(pos, ei), 0);
+ trace_add(SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
+ trace_add(TOTAL, score);
TraceStream << "\nUncertainty margin: White: " << to_cp(margins[WHITE])
<< ", Black: " << to_cp(margins[BLACK])
<< "\nScaling: " << std::noshowpos
- << std::setw(6) << 100.0 * phase/128.0 << "% MG, "
- << std::setw(6) << 100.0 * (1.0 - phase/128.0) << "% * "
+ << std::setw(6) << 100.0 * ei.mi->game_phase() / 128.0 << "% MG, "
+ << std::setw(6) << 100.0 * (1.0 - ei.mi->game_phase() / 128.0) << "% * "
<< std::setw(6) << (100.0 * sf) / SCALE_FACTOR_NORMAL << "% EG.\n"
<< "Total evaluation: " << to_cp(v);
}
@@ -426,7 +405,6 @@ void read_evaluation_uci_options(Color us) {
const int kingDangerThem = (us == WHITE ? KingDangerThem : KingDangerUs);
Weights[Mobility] = weight_option("Mobility (Middle Game)", "Mobility (Endgame)", WeightsInternal[Mobility]);
- Weights[PawnStructure] = weight_option("Pawn Structure (Middle Game)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
Weights[PassedPawns] = weight_option("Passed Pawns (Middle Game)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
Weights[Space] = weight_option("Space", "Space", WeightsInternal[Space]);
Weights[kingDangerUs] = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
@@ -459,12 +437,12 @@ namespace {
if ( pos.piece_count(Us, QUEEN)
&& pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame)
{
- ei.kingZone[Us] = (b | (Us == WHITE ? b >> 8 : b << 8));
+ ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
b &= ei.attackedBy[Us][PAWN];
ei.kingAttackersCount[Us] = b ? count_1s(b) / 2 : 0;
ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
} else
- ei.kingZone[Us] = ei.kingAttackersCount[Us] = 0;
+ ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0;
}
@@ -484,8 +462,8 @@ namespace {
// no minor piece which can exchange the outpost piece.
if (bonus && bit_is_set(ei.attackedBy[Us][PAWN], s))
{
- if ( pos.pieces(KNIGHT, Them) == EmptyBoardBB
- && (SquaresByColorBB[square_color(s)] & pos.pieces(BISHOP, Them)) == EmptyBoardBB)
+ if ( !pos.pieces(KNIGHT, Them)
+ && !(SquaresByColorBB[color_of(s)] & pos.pieces(BISHOP, Them)))
bonus += bonus + bonus / 2;
else
bonus += bonus / 2;
@@ -503,16 +481,16 @@ namespace {
Square s, ksq;
int mob;
File f;
- Score bonus = SCORE_ZERO;
+ Score score = SCORE_ZERO;
const BitCountType Full = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64 : CNT32;
const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square* ptr = pos.piece_list_begin(Us, Piece);
+ const Square* pl = pos.piece_list(Us, Piece);
- ei.attackedBy[Us][Piece] = EmptyBoardBB;
+ ei.attackedBy[Us][Piece] = 0;
- while ((s = *ptr++) != SQ_NONE)
+ while ((s = *pl++) != SQ_NONE)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
if (Piece == KNIGHT || Piece == QUEEN)
@@ -528,7 +506,7 @@ namespace {
ei.attackedBy[Us][Piece] |= b;
// King attacks
- if (b & ei.kingZone[Us])
+ if (b & ei.kingRing[Them])
{
ei.kingAttackersCount[Us]++;
ei.kingAttackersWeight[Us] += KingAttackWeights[Piece];
@@ -546,18 +524,19 @@ namespace {
// Decrease score if we are attacked by an enemy pawn. Remaining part
// of threat evaluation must be done later when we have full attack info.
if (bit_is_set(ei.attackedBy[Them][PAWN], s))
- bonus -= ThreatedByPawnPenalty[Piece];
+ score -= ThreatenedByPawnPenalty[Piece];
// Bishop and knight outposts squares
- if ((Piece == BISHOP || Piece == KNIGHT) && pos.square_is_weak(s, Us))
- bonus += evaluate_outposts(pos, ei, s);
+ if ( (Piece == BISHOP || Piece == KNIGHT)
+ && !(pos.pieces(PAWN, Them) & attack_span_mask(Us, s)))
+ score += evaluate_outposts(pos, ei, s);
// Queen or rook on 7th rank
if ( (Piece == ROOK || Piece == QUEEN)
&& relative_rank(Us, s) == RANK_7
&& relative_rank(Us, pos.king_square(Them)) == RANK_8)
{
- bonus += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+ score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
}
// Special extra evaluation for bishops
@@ -568,15 +547,15 @@ namespace {
// problem, especially when that pawn is also blocked.
if (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))
{
- Square d = pawn_push(Us) + (square_file(s) == FILE_A ? DELTA_E : DELTA_W);
+ Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
if (pos.piece_on(s + d) == make_piece(Us, PAWN))
{
if (!pos.square_is_empty(s + d + pawn_push(Us)))
- bonus -= 2*TrappedBishopA1H1Penalty;
+ score -= 2*TrappedBishopA1H1Penalty;
else if (pos.piece_on(s + 2*d) == make_piece(Us, PAWN))
- bonus -= TrappedBishopA1H1Penalty;
+ score -= TrappedBishopA1H1Penalty;
else
- bonus -= TrappedBishopA1H1Penalty / 2;
+ score -= TrappedBishopA1H1Penalty / 2;
}
}
}
@@ -585,13 +564,13 @@ namespace {
if (Piece == ROOK)
{
// Open and half-open files
- f = square_file(s);
+ f = file_of(s);
if (ei.pi->file_is_half_open(Us, f))
{
if (ei.pi->file_is_half_open(Them, f))
- bonus += RookOpenFileBonus;
+ score += RookOpenFileBonus;
else
- bonus += RookHalfOpenFileBonus;
+ score += RookHalfOpenFileBonus;
}
// Penalize rooks which are trapped inside a king. Penalize more if
@@ -601,31 +580,31 @@ namespace {
ksq = pos.king_square(Us);
- if ( square_file(ksq) >= FILE_E
- && square_file(s) > square_file(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
+ if ( file_of(ksq) >= FILE_E
+ && file_of(s) > file_of(ksq)
+ && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
{
// Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_right(Us, square_file(ksq)))
- bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
+ if (!ei.pi->has_open_file_to_right(Us, file_of(ksq)))
+ score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
: (TrappedRookPenalty - mob * 16), 0);
}
- else if ( square_file(ksq) <= FILE_D
- && square_file(s) < square_file(ksq)
- && (relative_rank(Us, ksq) == RANK_1 || square_rank(ksq) == square_rank(s)))
+ else if ( file_of(ksq) <= FILE_D
+ && file_of(s) < file_of(ksq)
+ && (relative_rank(Us, ksq) == RANK_1 || rank_of(ksq) == rank_of(s)))
{
// Is there a half-open file between the king and the edge of the board?
- if (!ei.pi->has_open_file_to_left(Us, square_file(ksq)))
- bonus -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
+ if (!ei.pi->has_open_file_to_left(Us, file_of(ksq)))
+ score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
: (TrappedRookPenalty - mob * 16), 0);
}
}
}
if (Trace)
- TracedTerms[Us][Piece] = bonus;
+ TracedScores[Us][Piece] = score;
- return bonus;
+ return score;
}
@@ -638,10 +617,10 @@ namespace {
const Color Them = (Us == WHITE ? BLACK : WHITE);
Bitboard b;
- Score bonus = SCORE_ZERO;
+ Score score = SCORE_ZERO;
// Enemy pieces not defended by a pawn and under our attack
- Bitboard weakEnemies = pos.pieces_of_color(Them)
+ Bitboard weakEnemies = pos.pieces(Them)
& ~ei.attackedBy[Them][PAWN]
& ei.attackedBy[Us][0];
if (!weakEnemies)
@@ -656,9 +635,9 @@ namespace {
if (b)
for (PieceType pt2 = PAWN; pt2 < KING; pt2++)
if (b & pos.pieces(pt2))
- bonus += ThreatBonus[pt1][pt2];
+ score += ThreatBonus[pt1][pt2];
}
- return bonus;
+ return score;
}
@@ -670,21 +649,21 @@ namespace {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Score bonus = mobility = SCORE_ZERO;
+ Score score = mobility = SCORE_ZERO;
// Do not include in mobility squares protected by enemy pawns or occupied by our pieces
- const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces_of_color(Us));
+ const Bitboard mobilityArea = ~(ei.attackedBy[Them][PAWN] | pos.pieces(Us));
- bonus += evaluate_pieces(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces(pos, ei, mobility, mobilityArea);
- bonus += evaluate_pieces(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces(pos, ei, mobility, mobilityArea);
+ score += evaluate_pieces(pos, ei, mobility, mobilityArea);
// Sum up all attacked squares
ei.attackedBy[Us][0] = ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT]
| ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
| ei.attackedBy[Us][QUEEN] | ei.attackedBy[Us][KING];
- return bonus;
+ return score;
}
@@ -701,7 +680,7 @@ namespace {
const Square ksq = pos.king_square(Us);
// King shelter
- Score bonus = ei.pi->king_shelter(pos, ksq);
+ Score score = ei.pi->king_shelter(pos, ksq);
// King safety. This is quite complicated, and is almost certainly far
// from optimally tuned.
@@ -720,14 +699,14 @@ namespace {
// the number and types of the enemy's attacking pieces, the number of
// attacked and undefended squares around our king, the square of the
// king, and the quality of the pawn shelter.
- attackUnits = Min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+ attackUnits = std::min(25, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
+ 3 * (ei.kingAdjacentZoneAttacksCount[Them] + count_1s(undefended))
+ InitKingDanger[relative_square(Us, ksq)]
- mg_value(ei.pi->king_shelter(pos, ksq)) / 32;
// Analyse enemy's safe queen contact checks. First find undefended
// squares around the king attacked by enemy queen...
- b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces_of_color(Them);
+ b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
if (b)
{
// ...then remove squares not supported by another enemy piece
@@ -741,7 +720,7 @@ namespace {
// Analyse enemy's safe rook contact checks. First find undefended
// squares around the king attacked by enemy rooks...
- b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces_of_color(Them);
+ b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
// Consider only squares where the enemy rook gives check
b &= RookPseudoAttacks[ksq];
@@ -758,7 +737,7 @@ namespace {
}
// Analyse enemy's safe distance checks for sliders and knights
- safe = ~(pos.pieces_of_color(Them) | ei.attackedBy[Us][0]);
+ safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
b1 = pos.attacks_from(ksq) & safe;
b2 = pos.attacks_from(ksq) & safe;
@@ -784,21 +763,21 @@ namespace {
attackUnits += KnightCheckBonus * count_1s(b);
// To index KingDangerTable[] attackUnits must be in [0, 99] range
- attackUnits = Min(99, Max(0, attackUnits));
+ attackUnits = std::min(99, std::max(0, attackUnits));
// Finally, extract the king danger score from the KingDangerTable[]
// array and subtract the score from evaluation. Set also margins[]
// value that will be used for pruning because this value can sometimes
// be very big, and so capturing a single attacking piece can therefore
// result in a score change far bigger than the value of the captured piece.
- bonus -= KingDangerTable[Us][attackUnits];
+ score -= KingDangerTable[Us][attackUnits];
margins[Us] += mg_value(KingDangerTable[Us][attackUnits]);
}
if (Trace)
- TracedTerms[Us][KING] = bonus;
+ TracedScores[Us][KING] = score;
- return bonus;
+ return score;
}
@@ -809,9 +788,10 @@ namespace {
const Color Them = (Us == WHITE ? BLACK : WHITE);
- Score bonus = SCORE_ZERO;
- Bitboard squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
- Bitboard b = ei.pi->passed_pawns(Us);
+ Bitboard b, squaresToQueen, defendedSquares, unsafeSquares, supportingPawns;
+ Score score = SCORE_ZERO;
+
+ b = ei.pi->passed_pawns(Us);
if (!b)
return SCORE_ZERO;
@@ -833,9 +813,12 @@ namespace {
Square blockSq = s + pawn_push(Us);
// Adjust bonus based on kings proximity
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 3 * rr);
- ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
- ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 6 * rr);
+ ebonus += Value(square_distance(pos.king_square(Them), blockSq) * 5 * rr);
+ ebonus -= Value(square_distance(pos.king_square(Us), blockSq) * 2 * rr);
+
+ // If blockSq is not the queening square then consider also a second push
+ if (rank_of(blockSq) != (Us == WHITE ? RANK_8 : RANK_1))
+ ebonus -= Value(square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr);
// If the pawn is free to advance, increase bonus
if (pos.square_is_empty(blockSq))
@@ -850,7 +833,7 @@ namespace {
&& (squares_in_front_of(Them, s) & pos.pieces(ROOK, QUEEN, Them) & pos.attacks_from(s)))
unsafeSquares = squaresToQueen;
else
- unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces_of_color(Them));
+ unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
// If there aren't enemy attacks or pieces along the path to queen give
// huge bonus. Even bigger if we protect the pawn's path.
@@ -862,19 +845,15 @@ namespace {
// If yes, big bonus (but smaller than when there are no enemy attacks),
// if no, somewhat smaller bonus.
ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
-
- // At last, add a small bonus when there are no *friendly* pieces
- // in the pawn's path.
- if (!(squaresToQueen & pos.pieces_of_color(Us)))
- ebonus += Value(rr);
}
} // rr != 0
// Increase the bonus if the passed pawn is supported by a friendly pawn
// on the same rank and a bit smaller if it's on the previous rank.
- supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(s);
+ supportingPawns = pos.pieces(PAWN, Us) & neighboring_files_bb(file_of(s));
if (supportingPawns & rank_bb(s))
ebonus += Value(r * 20);
+
else if (supportingPawns & rank_bb(s - pawn_push(Us)))
ebonus += Value(r * 12);
@@ -884,181 +863,183 @@ namespace {
// we try the following: Increase the value for rook pawns if the
// other side has no pieces apart from a knight, and decrease the
// value if the other side has a rook or queen.
- if (square_file(s) == FILE_A || square_file(s) == FILE_H)
+ if (file_of(s) == FILE_A || file_of(s) == FILE_H)
{
if (pos.non_pawn_material(Them) <= KnightValueMidgame)
ebonus += ebonus / 4;
else if (pos.pieces(ROOK, QUEEN, Them))
ebonus -= ebonus / 4;
}
- bonus += make_score(mbonus, ebonus);
+ score += make_score(mbonus, ebonus);
} while (b);
// Add the scores to the middle game and endgame eval
- return apply_weight(bonus, Weights[PassedPawns]);
+ return apply_weight(score, Weights[PassedPawns]);
}
- // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides
+
+ // evaluate_unstoppable_pawns() evaluates the unstoppable passed pawns for both sides, this is quite
+ // conservative and returns a winning score only when we are very sure that the pawn is winning.
+
template
Score evaluate_unstoppable_pawns(const Position& pos, EvalInfo& ei) {
const BitCountType Max15 = HasPopCnt ? CNT_POPCNT : CpuIs64Bit ? CNT64_MAX15 : CNT32_MAX15;
- // Step 1. Hunt for unstoppable pawns. If we find at least one, record how many plies
- // are required for promotion
- int pliesToGo[2] = {256, 256};
+ Bitboard b, b2, blockers, supporters, queeningPath, candidates;
+ Square s, blockSq, queeningSquare;
+ Color c, winnerSide, loserSide;
+ bool pathDefended, opposed;
+ int pliesToGo, movesToGo, oppMovesToGo, sacptg, blockersCount, minKingDist, kingptg, d;
+ int pliesToQueen[] = { 256, 256 };
- for (Color c = WHITE; c <= BLACK; c++)
+ // Step 1. Hunt for unstoppable passed pawns. If we find at least one,
+ // record how many plies are required for promotion.
+ for (c = WHITE; c <= BLACK; c++)
{
// Skip if other side has non-pawn pieces
- if (pos.non_pawn_material(opposite_color(c)))
+ if (pos.non_pawn_material(flip(c)))
continue;
- Bitboard b = ei.pi->passed_pawns(c);
+ b = ei.pi->passed_pawns(c);
while (b)
{
- Square s = pop_1st_bit(&b);
- Square queeningSquare = relative_square(c, make_square(square_file(s), RANK_8));
+ s = pop_1st_bit(&b);
+ queeningSquare = relative_square(c, make_square(file_of(s), RANK_8));
+ queeningPath = squares_in_front_of(c, s);
- int mtg = RANK_8 - relative_rank(c, s) - int(relative_rank(c, s) == RANK_2);
- int oppmtg = square_distance(pos.king_square(opposite_color(c)), queeningSquare) - int(c != pos.side_to_move());
- bool pathDefended = ((ei.attackedBy[c][0] & squares_in_front_of(c, s)) == squares_in_front_of(c, s));
+ // Compute plies to queening and check direct advancement
+ movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
+ oppMovesToGo = square_distance(pos.king_square(flip(c)), queeningSquare) - int(c != pos.side_to_move());
+ pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
- if (mtg >= oppmtg && !pathDefended)
+ if (movesToGo >= oppMovesToGo && !pathDefended)
continue;
- int blockerCount = count_1s(squares_in_front_of(c, s) & pos.occupied_squares());
- mtg += blockerCount;
+ // Opponent king cannot block because path is defended and position
+ // is not in check. So only friendly pieces can be blockers.
+ assert(!pos.in_check());
+ assert((queeningPath & pos.occupied_squares()) == (queeningPath & pos.pieces(c)));
- if (mtg >= oppmtg && !pathDefended)
- continue;
+ // Add moves needed to free the path from friendly pieces and retest condition
+ movesToGo += count_1s(queeningPath & pos.pieces(c));
- int ptg = 2 * mtg - int(c == pos.side_to_move());
+ if (movesToGo >= oppMovesToGo && !pathDefended)
+ continue;
- if (ptg < pliesToGo[c])
- pliesToGo[c] = ptg;
+ pliesToGo = 2 * movesToGo - int(c == pos.side_to_move());
+ pliesToQueen[c] = std::min(pliesToQueen[c], pliesToGo);
}
}
- // Step 2. If either side cannot promote at least three plies before the other side then
- // situation becomes too complex and we give up. Otherwise we determine the possibly "winning side"
- if (abs(pliesToGo[WHITE] - pliesToGo[BLACK]) < 3)
- return make_score(0, 0);
+ // Step 2. If either side cannot promote at least three plies before the other side then situation
+ // becomes too complex and we give up. Otherwise we determine the possibly "winning side"
+ if (abs(pliesToQueen[WHITE] - pliesToQueen[BLACK]) < 3)
+ return SCORE_ZERO;
- Color winnerSide = (pliesToGo[WHITE] < pliesToGo[BLACK] ? WHITE : BLACK);
- Color loserSide = opposite_color(winnerSide);
+ winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
+ loserSide = flip(winnerSide);
// Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
- // We collect the potential candidates in potentialBB.
- Bitboard pawnBB = pos.pieces(PAWN, loserSide);
- Bitboard potentialBB = pawnBB;
- const Bitboard passedBB = ei.pi->passed_pawns(loserSide);
+ b = candidates = pos.pieces(PAWN, loserSide);
- while(pawnBB)
+ while (b)
{
- Square psq = pop_1st_bit(&pawnBB);
-
- // Check direct advancement
- int mtg = RANK_8 - relative_rank(loserSide, psq) - int(relative_rank(loserSide, psq) == RANK_2);
- int ptg = 2 * mtg - int(loserSide == pos.side_to_move());
-
- // Check if (without even considering any obstacles) we're too far away
- if (pliesToGo[winnerSide] + 3 <= ptg)
- {
- clear_bit(&potentialBB, psq);
- continue;
- }
+ s = pop_1st_bit(&b);
- // If this is passed pawn, then it _may_ promote in time. We give up.
- if (bit_is_set(passedBB, psq))
- return make_score(0, 0);
+ // Compute plies from queening
+ queeningSquare = relative_square(loserSide, make_square(file_of(s), RANK_8));
+ movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
+ pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
- // Doubled pawn is worthless
- if (squares_in_front_of(loserSide, psq) & (pos.pieces(PAWN, loserSide)))
- {
- clear_bit(&potentialBB, psq);
- continue;
- }
+ // Check if (without even considering any obstacles) we're too far away or doubled
+ if ( pliesToQueen[winnerSide] + 3 <= pliesToGo
+ || (squares_in_front_of(loserSide, s) & pos.pieces(PAWN, loserSide)))
+ clear_bit(&candidates, s);
}
- // Step 4. Check new passed pawn creation through king capturing and sacrifises
- pawnBB = potentialBB;
+ // If any candidate is already a passed pawn it _may_ promote in time. We give up.
+ if (candidates & ei.pi->passed_pawns(loserSide))
+ return SCORE_ZERO;
+
+ // Step 4. Check new passed pawn creation through king capturing and pawn sacrifices
+ b = candidates;
- while(pawnBB)
+ while (b)
{
- Square psq = pop_1st_bit(&pawnBB);
+ s = pop_1st_bit(&b);
+ sacptg = blockersCount = 0;
+ minKingDist = kingptg = 256;
- int mtg = RANK_8 - relative_rank(loserSide, psq) - int(relative_rank(loserSide, psq) == RANK_2);
- int ptg = 2 * mtg - int(loserSide == pos.side_to_move());
+ // Compute plies from queening
+ queeningSquare = relative_square(loserSide, make_square(file_of(s), RANK_8));
+ movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(loserSide, s) == RANK_2);
+ pliesToGo = 2 * movesToGo - int(loserSide == pos.side_to_move());
- // Generate list of obstacles
- Bitboard obsBB = passed_pawn_mask(loserSide, psq) & pos.pieces(PAWN, winnerSide);
- const bool pawnIsOpposed = squares_in_front_of(loserSide, psq) & obsBB;
- assert(obsBB);
+ // Generate list of blocking pawns and supporters
+ supporters = neighboring_files_bb(file_of(s)) & candidates;
+ opposed = squares_in_front_of(loserSide, s) & pos.pieces(PAWN, winnerSide);
+ blockers = passed_pawn_mask(loserSide, s) & pos.pieces(PAWN, winnerSide);
- // How many plies does it take to remove all the obstacles?
- int sacptg = 0;
- int realObsCount = 0;
- int minKingDist = 256;
+ assert(blockers);
- while(obsBB)
+ // How many plies does it take to remove all the blocking pawns?
+ while (blockers)
{
- Square obSq = pop_1st_bit(&obsBB);
- int minMoves = 256;
+ blockSq = pop_1st_bit(&blockers);
+ movesToGo = 256;
- // Check pawns that can give support to overcome obstacle (Eg. wp: a4,b4 bp: b2. b4 is giving support)
- if (!pawnIsOpposed && square_file(psq) != square_file(obSq))
+ // Check pawns that can give support to overcome obstacle, for instance
+ // black pawns: a4, b4 white: b2 then pawn in b4 is giving support.
+ if (!opposed)
{
- Bitboard supBB = in_front_bb(winnerSide, Square(obSq + (winnerSide == WHITE ? 8 : -8)))
- & neighboring_files_bb(psq) & potentialBB;
+ b2 = supporters & in_front_bb(winnerSide, blockSq + pawn_push(winnerSide));
- while(supBB) // This while-loop could be replaced with supSq = LSB/MSB(supBB) (depending on color)
+ while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
{
- Square supSq = pop_1st_bit(&supBB);
- int dist = square_distance(obSq, supSq);
- minMoves = Min(minMoves, dist - 2);
+ d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
+ movesToGo = std::min(movesToGo, d);
}
-
}
- // Check pawns that can be sacrifised
- Bitboard sacBB = passed_pawn_mask(winnerSide, obSq) & neighboring_files_bb(obSq) & potentialBB & ~(1ULL << psq);
+ // Check pawns that can be sacrificed against the blocking pawn
+ b2 = attack_span_mask(winnerSide, blockSq) & candidates & ~(1ULL << s);
- while(sacBB) // This while-loop could be replaced with sacSq = LSB/MSB(sacBB) (depending on color)
+ while (b2) // This while-loop could be replaced with LSB/MSB (depending on color)
{
- Square sacSq = pop_1st_bit(&sacBB);
- int dist = square_distance(obSq, sacSq);
- minMoves = Min(minMoves, dist - 2);
+ d = square_distance(blockSq, pop_1st_bit(&b2)) - 2;
+ movesToGo = std::min(movesToGo, d);
}
- // If obstacle can be destroyed with immediate pawn sacrifise, it's not real obstacle
- if (minMoves <= 0)
+ // If obstacle can be destroyed with an immediate pawn exchange / sacrifice,
+ // it's not a real obstacle and we have nothing to add to pliesToGo.
+ if (movesToGo <= 0)
continue;
- // Pawn sac calculations
- sacptg += minMoves * 2;
+ // Plies needed to sacrifice against all the blocking pawns
+ sacptg += movesToGo * 2;
+ blockersCount++;
- // King capture calc
- realObsCount++;
- int kingDist = square_distance(pos.king_square(loserSide), obSq);
- minKingDist = Min(minKingDist, kingDist);
+ // Plies needed for the king to capture all the blocking pawns
+ d = square_distance(pos.king_square(loserSide), blockSq);
+ minKingDist = std::min(minKingDist, d);
+ kingptg = (minKingDist + blockersCount) * 2;
}
- // Check if pawn sac plan _may_ save the day
- if (pliesToGo[winnerSide] + 3 > ptg + sacptg)
- return make_score(0, 0);
+ // Check if pawn sacrifice plan _may_ save the day
+ if (pliesToQueen[winnerSide] + 3 > pliesToGo + sacptg)
+ return SCORE_ZERO;
// Check if king capture plan _may_ save the day (contains some false positives)
- int kingptg = (minKingDist + realObsCount) * 2;
- if (pliesToGo[winnerSide] + 3 > ptg + kingptg)
- return make_score(0, 0);
+ if (pliesToQueen[winnerSide] + 3 > pliesToGo + kingptg)
+ return SCORE_ZERO;
}
- // Step 5. Assign bonus
- const int Sign[2] = {1, -1};
- return Sign[winnerSide] * make_score(0, (Value) 0x500 - 0x20 * pliesToGo[winnerSide]);
+ // Winning pawn is unstoppable and will promote as first, return big score
+ Score score = make_score(0, (Value) 0x500 - 0x20 * pliesToQueen[winnerSide]);
+ return winnerSide == WHITE ? score : -score;
}
@@ -1094,8 +1075,8 @@ namespace {
// apply_weight() applies an evaluation weight to a value trying to prevent overflow
inline Score apply_weight(Score v, Score w) {
- return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
- (int(eg_value(v)) * eg_value(w)) / 0x100);
+ return make_score((int(mg_value(v)) * mg_value(w)) / 0x100,
+ (int(eg_value(v)) * eg_value(w)) / 0x100);
}
@@ -1142,9 +1123,9 @@ namespace {
t[i] = Value(int(0.4 * i * i));
if (i > 0)
- t[i] = Min(t[i], t[i - 1] + MaxSlope);
+ t[i] = std::min(t[i], t[i - 1] + MaxSlope);
- t[i] = Min(t[i], Peak);
+ t[i] = std::min(t[i], Peak);
}
// Then apply the weights and get the final KingDangerTable[] array
@@ -1154,29 +1135,40 @@ namespace {
}
+ // A couple of little helpers used by tracing code, to_cp() converts a value to
+ // a double in centipawns scale, trace_add() stores white and black scores.
+
+ double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
+
+ void trace_add(int idx, Score wScore, Score bScore) {
+
+ TracedScores[WHITE][idx] = wScore;
+ TracedScores[BLACK][idx] = bScore;
+ }
+
// trace_row() is an helper function used by tracing code to register the
// values of a single evaluation term.
void trace_row(const char *name, int idx) {
- Score term_w = TracedTerms[WHITE][idx];
- Score term_b = TracedTerms[BLACK][idx];
+ Score wScore = TracedScores[WHITE][idx];
+ Score bScore = TracedScores[BLACK][idx];
switch (idx) {
case PST: case IMBALANCE: case PAWN: case UNSTOPPABLE: case TOTAL:
TraceStream << std::setw(20) << name << " | --- --- | --- --- | "
- << std::setw(6) << to_cp(mg_value(term_w)) << " "
- << std::setw(6) << to_cp(eg_value(term_w)) << " \n";
+ << std::setw(6) << to_cp(mg_value(wScore)) << " "
+ << std::setw(6) << to_cp(eg_value(wScore)) << " \n";
break;
default:
TraceStream << std::setw(20) << name << " | " << std::noshowpos
- << std::setw(5) << to_cp(mg_value(term_w)) << " "
- << std::setw(5) << to_cp(eg_value(term_w)) << " | "
- << std::setw(5) << to_cp(mg_value(term_b)) << " "
- << std::setw(5) << to_cp(eg_value(term_b)) << " | "
+ << std::setw(5) << to_cp(mg_value(wScore)) << " "
+ << std::setw(5) << to_cp(eg_value(wScore)) << " | "
+ << std::setw(5) << to_cp(mg_value(bScore)) << " "
+ << std::setw(5) << to_cp(eg_value(bScore)) << " | "
<< std::showpos
- << std::setw(6) << to_cp(mg_value(term_w - term_b)) << " "
- << std::setw(6) << to_cp(eg_value(term_w - term_b)) << " \n";
+ << std::setw(6) << to_cp(mg_value(wScore - bScore)) << " "
+ << std::setw(6) << to_cp(eg_value(wScore - bScore)) << " \n";
}
}
}
@@ -1193,7 +1185,7 @@ std::string trace_evaluate(const Position& pos) {
TraceStream.str("");
TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
- memset(TracedTerms, 0, 2 * 16 * sizeof(Score));
+ memset(TracedScores, 0, 2 * 16 * sizeof(Score));
do_evaluate(pos, margin);